TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Babić, Biljana M.
AU  - Gajić Krstajić, Ljiljana
AU  - Radmilović, Velimir R.
AU  - Krstajić, Nedeljko
AU  - Vračar, Ljiljana
PY  - 2010
UR  - https://dais.sanu.ac.rs/123456789/3418
AB  - In order to point out the effect of the support to the catalyst for oxygen reduction reaction nano-crystalline Nb-doped TiO2 was synthesized through a modified sol-gel route procedure. The specific surface area of the support, SBET, and pore size distribution, were calculated from the adsorption isotherms using the gravimetric McBain method. The support was characterized by X-ray diffraction (XRD) technique. The borohydride reduction method was used to prepare Nb-TiO2 supported Pt (20 wt.%) catalyst. The synthesized catalyst was analyzed by TEM technique. Finally, the catalytic activity of this new catalyst for oxygen reduction reaction was investigated in acid solution, in the absence and the presence of methanol, and its activity was compared towards the results on C/Pt catalysts. Kinetic analysis reveals that the oxygen reduction reaction on Nb-TiO2/Pt catalyst follows four-electron process leading to water, as in the case of C/Pt electrode, but the Tafel plots normalized to the electrochemically active surface area show very remarkable enhancement in activity of Nb-TiO2/Pt expressed through the value of the current density at the constant potential. Moreover, Nb-TiO2/Pt catalyst exhibits higher methanol tolerance during the oxygen reduction reaction than the C/Pt catalyst. The enhancement in the activity of Nb-TiO2/Pt is consequence of both: the interactions of Pt nanoparticles with the support and the energy shift of the surface d-states with respect to the Fermi level what changes the surface reactivity. © 2010 Elsevier B.V.
PB  - Elsevier
T2  - Journal of Power Sources
T1  - Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction
SP  - 3961
EP  - 3968
VL  - 195
IS  - 13
DO  - 10.1016/j.jpowsour.2010.01.035
UR  - https://hdl.handle.net/21.15107/rcub_dais_3418
ER  - 

@article{
author = "Elezović, Nevenka R. and Babić, Biljana M. and Gajić Krstajić, Ljiljana and Radmilović, Velimir R. and Krstajić, Nedeljko and Vračar, Ljiljana",
year = "2010",
abstract = "In order to point out the effect of the support to the catalyst for oxygen reduction reaction nano-crystalline Nb-doped TiO2 was synthesized through a modified sol-gel route procedure. The specific surface area of the support, SBET, and pore size distribution, were calculated from the adsorption isotherms using the gravimetric McBain method. The support was characterized by X-ray diffraction (XRD) technique. The borohydride reduction method was used to prepare Nb-TiO2 supported Pt (20 wt.%) catalyst. The synthesized catalyst was analyzed by TEM technique. Finally, the catalytic activity of this new catalyst for oxygen reduction reaction was investigated in acid solution, in the absence and the presence of methanol, and its activity was compared towards the results on C/Pt catalysts. Kinetic analysis reveals that the oxygen reduction reaction on Nb-TiO2/Pt catalyst follows four-electron process leading to water, as in the case of C/Pt electrode, but the Tafel plots normalized to the electrochemically active surface area show very remarkable enhancement in activity of Nb-TiO2/Pt expressed through the value of the current density at the constant potential. Moreover, Nb-TiO2/Pt catalyst exhibits higher methanol tolerance during the oxygen reduction reaction than the C/Pt catalyst. The enhancement in the activity of Nb-TiO2/Pt is consequence of both: the interactions of Pt nanoparticles with the support and the energy shift of the surface d-states with respect to the Fermi level what changes the surface reactivity. © 2010 Elsevier B.V.",
publisher = "Elsevier",
journal = "Journal of Power Sources",
title = "Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction",
pages = "3961-3968",
volume = "195",
number = "13",
doi = "10.1016/j.jpowsour.2010.01.035",
url = "https://hdl.handle.net/21.15107/rcub_dais_3418"
}

Elezović, N. R., Babić, B. M., Gajić Krstajić, L., Radmilović, V. R., Krstajić, N.,& Vračar, L.. (2010). Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction. in Journal of Power Sources
Elsevier., 195(13), 3961-3968.
https://doi.org/10.1016/j.jpowsour.2010.01.035
https://hdl.handle.net/21.15107/rcub_dais_3418

Elezović NR, Babić BM, Gajić Krstajić L, Radmilović VR, Krstajić N, Vračar L. Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction. in Journal of Power Sources. 2010;195(13):3961-3968.
doi:10.1016/j.jpowsour.2010.01.035
https://hdl.handle.net/21.15107/rcub_dais_3418 .

Elezović, Nevenka R., Babić, Biljana M., Gajić Krstajić, Ljiljana, Radmilović, Velimir R., Krstajić, Nedeljko, Vračar, Ljiljana, "Synthesis, characterization and electrocatalytical behavior of Nb-TiO2/Pt nanocatalyst for oxygen reduction reaction" in Journal of Power Sources, 195, no. 13 (2010):3961-3968,
https://doi.org/10.1016/j.jpowsour.2010.01.035 .,
https://hdl.handle.net/21.15107/rcub_dais_3418 .

TY  - CONF
AU  - Krstajić, Nedeljko
AU  - Elezović, Nevenka R.
AU  - Vračar, Ljiljana
AU  - Gajić Krstajić, Ljiljana
AU  - Radmilović, Velimir R.
PY  - 2009
UR  - https://dais.sanu.ac.rs/123456789/4956
AB  - Due to the importance of the HOR in fuel-cells technology, various Pt-based catalysts have been examined from the viewpoint of immunity of the electrocatalysis of the HOR from CO-poisoning of the anode catalysts. An appreciable improvement of the CO tolerance has been found at Pt with adatoms such as Ru, Sn [1,2], Pt-M (M=Ru, Rh, Os, W Sn) [3-5] based alloys, and Pt with oxides (RuOxHy) [6]. In the present work, the electrocatalytic of home made highly dispersed nano-sized MoOx-Pt/C catalysts prepared by the polyole method combined by MoOx post-deposition was investigated in the presence of CO, in 0.5 moldm-3 HClO4 solution. The partial pressure of CO in CO/H2 gas mixture was 100 ppm. Carbon monoxide was adsorbed on the RDE for various time interval with keeping the potential at 0.05 V (RHE). The coverage of CO was determined by applying the first potential sweep (from 0.04 to 1.20 V), in N2 saturated solution at potential scan rate of 0.1 Vs-1 and compared it with the sweep on the clean electrode, by measuring the decrease in the hydrogen desorption charge, ΔQH. MoOx(20%)Pt/C catalyst exhibits an excellent CO tolerance, as it was found that the reduction in kinetic current, Ik, is negligible even at ΘCO = 0.46. It was found for this catalyst too, that the CO adsorption rate was much slower than that of Pt and the Pt sites for HOR were not so rigidly blocked by adsorbed CO partially due to its enhanced mobility, resulting from their modified electronic structure of surface Pt sites. Voltammetric studies suggest that an excellent CO tolerance of this catalyst could be also result of the oxidation of adsorbed CO to CO2 by oxophilic MoOx species at low overpotentials by a redox-mediated mechanism.
PB  - Belgrade : Institute of Technical Sciences of SASA
C3  - Programme and The Book of Abstracts / Eleventh Annual Conference YUCOMAT 2009, Herceg Novi, August 31 – September 4, 2009
T1  - Kinetics of the hydrogen oxidation on pt modified MoOx nano-sized catalyst in the presence of carbon monoxide
SP  - 85
EP  - 85
UR  - https://hdl.handle.net/21.15107/rcub_dais_4956
ER  - 

@conference{
author = "Krstajić, Nedeljko and Elezović, Nevenka R. and Vračar, Ljiljana and Gajić Krstajić, Ljiljana and Radmilović, Velimir R.",
year = "2009",
abstract = "Due to the importance of the HOR in fuel-cells technology, various Pt-based catalysts have been examined from the viewpoint of immunity of the electrocatalysis of the HOR from CO-poisoning of the anode catalysts. An appreciable improvement of the CO tolerance has been found at Pt with adatoms such as Ru, Sn [1,2], Pt-M (M=Ru, Rh, Os, W Sn) [3-5] based alloys, and Pt with oxides (RuOxHy) [6]. In the present work, the electrocatalytic of home made highly dispersed nano-sized MoOx-Pt/C catalysts prepared by the polyole method combined by MoOx post-deposition was investigated in the presence of CO, in 0.5 moldm-3 HClO4 solution. The partial pressure of CO in CO/H2 gas mixture was 100 ppm. Carbon monoxide was adsorbed on the RDE for various time interval with keeping the potential at 0.05 V (RHE). The coverage of CO was determined by applying the first potential sweep (from 0.04 to 1.20 V), in N2 saturated solution at potential scan rate of 0.1 Vs-1 and compared it with the sweep on the clean electrode, by measuring the decrease in the hydrogen desorption charge, ΔQH. MoOx(20%)Pt/C catalyst exhibits an excellent CO tolerance, as it was found that the reduction in kinetic current, Ik, is negligible even at ΘCO = 0.46. It was found for this catalyst too, that the CO adsorption rate was much slower than that of Pt and the Pt sites for HOR were not so rigidly blocked by adsorbed CO partially due to its enhanced mobility, resulting from their modified electronic structure of surface Pt sites. Voltammetric studies suggest that an excellent CO tolerance of this catalyst could be also result of the oxidation of adsorbed CO to CO2 by oxophilic MoOx species at low overpotentials by a redox-mediated mechanism.",
publisher = "Belgrade : Institute of Technical Sciences of SASA",
journal = "Programme and The Book of Abstracts / Eleventh Annual Conference YUCOMAT 2009, Herceg Novi, August 31 – September 4, 2009",
title = "Kinetics of the hydrogen oxidation on pt modified MoOx nano-sized catalyst in the presence of carbon monoxide",
pages = "85-85",
url = "https://hdl.handle.net/21.15107/rcub_dais_4956"
}

Krstajić, N., Elezović, N. R., Vračar, L., Gajić Krstajić, L.,& Radmilović, V. R.. (2009). Kinetics of the hydrogen oxidation on pt modified MoOx nano-sized catalyst in the presence of carbon monoxide. in Programme and The Book of Abstracts / Eleventh Annual Conference YUCOMAT 2009, Herceg Novi, August 31 – September 4, 2009
Belgrade : Institute of Technical Sciences of SASA., 85-85.
https://hdl.handle.net/21.15107/rcub_dais_4956

Krstajić N, Elezović NR, Vračar L, Gajić Krstajić L, Radmilović VR. Kinetics of the hydrogen oxidation on pt modified MoOx nano-sized catalyst in the presence of carbon monoxide. in Programme and The Book of Abstracts / Eleventh Annual Conference YUCOMAT 2009, Herceg Novi, August 31 – September 4, 2009. 2009;:85-85.
https://hdl.handle.net/21.15107/rcub_dais_4956 .

Krstajić, Nedeljko, Elezović, Nevenka R., Vračar, Ljiljana, Gajić Krstajić, Ljiljana, Radmilović, Velimir R., "Kinetics of the hydrogen oxidation on pt modified MoOx nano-sized catalyst in the presence of carbon monoxide" in Programme and The Book of Abstracts / Eleventh Annual Conference YUCOMAT 2009, Herceg Novi, August 31 – September 4, 2009 (2009):85-85,
https://hdl.handle.net/21.15107/rcub_dais_4956 .

TY  - JOUR
AU  - Elezović, Nevenka R.
AU  - Gajić Krstajić, Ljiljana
AU  - Radmilović, Velimir R.
AU  - Vračar, Ljiljana
AU  - Krstajić, Nedeljko
PY  - 2009
UR  - https://dais.sanu.ac.rs/123456789/3485
AB  - The influence of poisoning of Pt catalyst by CO on the kinetics and mechanism of H2 oxidation reaction (HOR) at Pt/C electrode in 0.5 mol dm-3 HClO4, saturated with H2 containing 100 ppm CO, was examined with rotating disc electrode (RDE) at 22 °C. Commercial carbon black, Vulcan XC-72 was used as support, while Pt/C catalyst was prepared by modified polyol synthesis method in an ethylene glycol (EG) solution. The kinetically controlled current (Ik) for the HOR at Pt/C decreases significantly at CO coverage (ΘCO) > 0.6. For ΘCO < 0.6 the HOR takes place through Tafel-Volmer mechanism with Tafel reaction as rate-determining step at the low CO coverage, while Volmer step controls the overall reaction rate at the medium CO coverage. When CO coverage is higher then 0.6, Heyrovsky-Volmer mechanism is operative for the HOR with Heyrovsky as the rate-determining step (rds). © 2008 Elsevier Ltd. All rights reserved.
PB  - Elsevier
T2  - Electrochimica Acta
T1  - Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction
SP  - 1375
EP  - 1382
VL  - 54
IS  - 4
DO  - 10.1016/j.electacta.2008.08.067
UR  - https://hdl.handle.net/21.15107/rcub_dais_3485
ER  - 

@article{
author = "Elezović, Nevenka R. and Gajić Krstajić, Ljiljana and Radmilović, Velimir R. and Vračar, Ljiljana and Krstajić, Nedeljko",
year = "2009",
abstract = "The influence of poisoning of Pt catalyst by CO on the kinetics and mechanism of H2 oxidation reaction (HOR) at Pt/C electrode in 0.5 mol dm-3 HClO4, saturated with H2 containing 100 ppm CO, was examined with rotating disc electrode (RDE) at 22 °C. Commercial carbon black, Vulcan XC-72 was used as support, while Pt/C catalyst was prepared by modified polyol synthesis method in an ethylene glycol (EG) solution. The kinetically controlled current (Ik) for the HOR at Pt/C decreases significantly at CO coverage (ΘCO) > 0.6. For ΘCO < 0.6 the HOR takes place through Tafel-Volmer mechanism with Tafel reaction as rate-determining step at the low CO coverage, while Volmer step controls the overall reaction rate at the medium CO coverage. When CO coverage is higher then 0.6, Heyrovsky-Volmer mechanism is operative for the HOR with Heyrovsky as the rate-determining step (rds). © 2008 Elsevier Ltd. All rights reserved.",
publisher = "Elsevier",
journal = "Electrochimica Acta",
title = "Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction",
pages = "1375-1382",
volume = "54",
number = "4",
doi = "10.1016/j.electacta.2008.08.067",
url = "https://hdl.handle.net/21.15107/rcub_dais_3485"
}

Elezović, N. R., Gajić Krstajić, L., Radmilović, V. R., Vračar, L.,& Krstajić, N.. (2009). Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction. in Electrochimica Acta
Elsevier., 54(4), 1375-1382.
https://doi.org/10.1016/j.electacta.2008.08.067
https://hdl.handle.net/21.15107/rcub_dais_3485

Elezović NR, Gajić Krstajić L, Radmilović VR, Vračar L, Krstajić N. Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction. in Electrochimica Acta. 2009;54(4):1375-1382.
doi:10.1016/j.electacta.2008.08.067
https://hdl.handle.net/21.15107/rcub_dais_3485 .

Elezović, Nevenka R., Gajić Krstajić, Ljiljana, Radmilović, Velimir R., Vračar, Ljiljana, Krstajić, Nedeljko, "Effect of chemisorbed carbon monoxide on Pt/C electrode on the mechanism of the hydrogen oxidation reaction" in Electrochimica Acta, 54, no. 4 (2009):1375-1382,
https://doi.org/10.1016/j.electacta.2008.08.067 .,
https://hdl.handle.net/21.15107/rcub_dais_3485 .